The universal soil-loss equation (USLE) suggests that soil erosion loss is a product of all but one of the following factors:
A) slope length.
B) climate.
C) vegetative cover.
D) sloped steepness.
E) soil drainage.
Question 2Which of the following statements is true?
A) Rill erosion is initiated before water concentrates in small 1-2 cm channels.
B) Gully erosion carries the most sediment away from lands in the United States.
C) Sheet erosion is most obvious from a distance.
D) Rill erosion is the most serious in forested areas.
E) Rill erosion channels can be removed by ordinary cultivation.
Question 3Sodic soils generally have a poor physical condition. To what is this most likely due?
A) impact of raindrops on the soil surface
B) precipitation of the Ca2+ and Mg2+ ions as carbonates
C) dispersal of the Na saturated soil colloids
D) low organic matter content
E) high content of smectite in the soils
Question 4Most chemical fertilizers are inorganic salts.
Indicate whether the statement is true or false
Question 5In explaining erosion processes to a friend, which of the following would you say about accelerated erosion?
A) It involves a much less rapid process than geological erosion.
B) It is greatly enhanced by the splash effect of raindrops impacting bare soil.
C) It refers to sediment carried by water flowing at ever greater velocity.
D) it removes more nitrogen from the surface soil than calcium
E) It is increasing in intensity in the United States, especially in the past 10 years.
Question 6Gypsum is the most widely used chemical for the reclamation of sodic soils. What characteristic likely accounts for this popularity?
A) Gypsum reacts with Na+ ions to form insoluble Na2SO4.
B) Gypsum is abundant and low priced.
C) Gypsum provides sulfates that attract Na+ from the exchange complex.
D) Gypsum forms sulfuric acid that helps reduce the soil pH.
E) Gypsum is quite insoluble so it remains in the soil for long periods of time.
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